Just because someone needs a break from a relationship doesn't mean they don't care about the other person. Obviously something is going on in her life that she prefers to try and handle alone. Giving her the break and time she needs can actually make your relationship better, stronger. Talk to her. Let her know you're there for her no matter what, that you will always love her and only want her to be happy. If it's meant to be, she'll be back but she needs time & space. Good luck to you.